1. Field of the Invention
The present invention relates generally to flush valves, such as diaphragm type flush valves. More particularly, the present invention relates to a filter and/or strainer for flush valves.
2. Related Art
Flush valves, such as those used with toilets, urinals, or water closets, and other diaphragm valves, have a valve body with a diaphragm movably disposed therein. The valve body has an inlet, typically formed in the side of the valve body, and an outlet, typically formed in the bottom of the valve body. The outlet includes an outlet pipe that extends into the valve body. The diaphragm moves between closed and open positions. In the closed position, the diaphragm is disposed against the outlet pipe over the outlet, preventing the flow of water through the valve. In the open position, the diaphragm is disposed away from the outlet pipe and the outlet, allowing the flow of water through the valve.
The diaphragm separates the valve body into separate chambers with the outlet pipe disposed in one chamber, and the diaphragm displacing into the opposite chamber. The inlet opens into the same chamber as the outlet, but the flow of water is prevented by the diaphragm being disposed against the outlet pipe. A bleed hole is formed in the diaphragm to allow water to flow from the outlet, though the bleed hole, and into the opposite chamber, thus equalizing pressure on both sides of the diaphragm. The outlet pipe causes the opposite side of the diaphragm to have a greater surface area. Thus, the force on the opposite side of the diaphragm is greater, and forces the diaphragm against the outlet pipe, keeping the valve closed. To open the valve, water is bled from the opposite chamber, reducing the pressure and causing the diaphragm to move away from the outlet pipe, and allowing the flow of water from the inlet to the outlet.
One disadvantage with typical flush valves or diaphragm valves is their tendency to become inoperative due to debris or contaminants in the water that clog the bleed hole, or that foul the seal between the diaphragm and outlet. It will be appreciated that a clog in the bleed hole can prevent the diaphragm from returning to the closed position, and thus prevent the valve from shutting off. Similarly, fouling the seal between the diaphragm and outlet also can cause the valve to run. It will be appreciated that a running valve can cause substantial water damage. In addition, it will be appreciated that such valves can require significant maintenance.
Various solutions have been proposed. For example, filters have been disposed in the plumbing prior to the valve. One disadvantage with this proposal is that the plumbing surrounding a valve typically is fixed, and thus difficult and/or expensive to clean or service. Similarly, special plumbing fixtures with filters disposed prior to the valve have been proposed. Such special plumbing fixtures, however, add cost to installation, and are difficult or impossible to implement with existing fixtures. As another example, filters coupled to the diaphragm have been proposed. One disadvantage with such filters is that they can interfere with the operation of the diaphragm. In addition, such filter system can be complicated. Furthermore, such filters have little surface area and can be more easily clogged.
It has been recognized that it would be advantageous to develop a filter or strainer for use with valves, such as diaphragm valves, and with urinals, toilets or water closets, that is easy to install, does not interfere with the operation of the valve or diaphragm, resists clogging, requires less servicing, and is inexpensive to implement.
The invention provides a filter device for a valve, such as a flush valve. The valve can include a valve body with a valve wall, a cavity therein, an inlet extending through the valve wall into the cavity, and an outlet pipe disposed in the cavity with an abutment edge. A diaphragm assembly can be movably disposed in the cavity of the valve body. The diaphragm assembly can include a portion that moves between 1) a closed position in which the portion is disposed against the abutment edge of the outlet pipe, and 2) an open position in which the portion is disposed away from the abutment edge of the outlet pipe. The filter advantageously can be disposed in the cavity of the valve body between the inlet and the outlet pipe, and can span an entire span between the outlet pipe and the valve wall.
The filter device can include a filter body with a mesh material associated with the filter body. A first opening can be formed in the filter body with an inner peripheral edge sized and shaped to seal about the outlet pipe. An outer peripheral edge of the filter body can be sized and shaped to seal against the cavity wall. Thus, the filter body can be sized and shaped to extend across the cavity of the valve between the inlet pipe and the valve wall.
In accordance with a more detailed aspect of the present invention, the filter body can further include a tubular shell sized and shaped to fit in the cavity and around the outlet pipe. A second opening can be formed in the upper end of the shell, larger than the first opening, and sized and shaped to seal against the valve wall of the cavity.
In accordance with another more detailed aspect of the present invention, the tubular shell can have a frusto-conical shape.
In accordance with another more detailed aspect of the present invention, the filter device can have an inner seal disposed around the inner peripheral edge. The inner seal can include a flexible material.
In accordance with another more detailed aspect of the present invention, the filter device can include an outer seal disposed around the outer peripheral edge. The outer seal can include a flexible material.
In accordance with another more detailed aspect of the present invention, the filter body can further include an inner ring with the first opening formed therein, and an outer ring forming the outer peripheral edge. The mesh material can be disposed between the inner and outer rings.
In accordance with another more detailed aspect of the present invention, a seam can be formed by opposing edges of the mesh material. A rib can extend between the inner and outer rings, and can close the seam.
A method for filtering water in a valve can include the steps of positioning a filter in a cavity of a valve between an inlet thereto and an outlet pipe, and between the inlet and a bleed hole of a diaphragm of the valve. The filter can be sealed around the outlet pipe of the valve. The filter can span an entire span between the outlet pipe and a valve wall with the filter. The filter can seal against the valve wall. Thus, all water entering the valve through the inlet passes though the filter prior to exiting through the outlet pipe, and prior to passing through the bleed hole in the diaphragm of the valve.
Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention.